IDeserializationCallback Interface

Indicates that a class is to be notified when deserialization of the entire object graph has been completed.

Namespace:  System.Runtime.Serialization
Assembly:  mscorlib (in mscorlib.dll)

'Declaration
<ComVisibleAttribute(True)> _
Public Interface IDeserializationCallback
'Usage
Dim instance As IDeserializationCallback

Notes to Implementers:

Implement the current interface as part of support for a method that is called when deserialization of the object graph is complete.

If an object needs to execute code on its child objects, it can delay this action, implement IDeserializationCallback, and execute the code only when it is called back on this interface.

Imports System
Imports System.IO
Imports System.Collections
Imports System.Runtime.Serialization.Formatters.Binary
Imports System.Runtime.Serialization

' This class is serializable and will have its OnDeserialization method 
' called after each instance of this class is deserialized.
<Serializable()> Class Circle
   Implements IDeserializationCallback
   Private m_radius As Double 

   ' To reduce the size of the serialization stream, the field below is  
   ' not serialized. This field is calculated when an object is constructed 
   ' or after an instance of this class is deserialized.
   <NonSerialized()> Public m_area As Double 

   Public Sub New(ByVal radius As Double)
      m_radius = radius
      m_area = Math.PI * radius * radius
   End Sub 

   Private Sub OnDeserialization(ByVal sender As Object) _
      Implements IDeserializationCallback.OnDeserialization
      ' After being deserialized, initialize the m_area field  
      ' using the deserialized m_radius value.
      m_area = Math.PI * m_radius * m_radius
   End Sub 

   Public Overrides Function ToString() As String 
      Return String.Format("radius={0}, area={1}", m_radius, m_area)
   End Function 
End Class 


Class Class1
   <STAThread()> Shared Sub Main()
      Serialize()
      Deserialize()
   End Sub 

   Shared Sub Serialize()
      Dim c As New Circle(10)
      Console.WriteLine("Object being serialized: " + c.ToString())

      ' To serialize the Circle, you must first open a stream for  
      ' writing. Use a file stream here. 
      Dim fs As New FileStream("DataFile.dat", FileMode.Create)

      ' Construct a BinaryFormatter and use it  
      ' to serialize the data to the stream. 
      Dim formatter As New BinaryFormatter
      Try
         formatter.Serialize(fs, c)
      Catch e As SerializationException
         Console.WriteLine("Failed to serialize. Reason: " + e.Message)
         Throw 
      Finally
         fs.Close()
      End Try 
   End Sub 


   Shared Sub Deserialize()
      ' Declare the Circle reference 
      Dim c As Circle = Nothing 

      ' Open the file containing the data that you want to deserialize. 
      Dim fs As New FileStream("DataFile.dat", FileMode.Open)
      Try 
         Dim formatter As New BinaryFormatter

         ' Deserialize the Circle from the file and  
         ' assign the reference to the local variable.
         c = CType(formatter.Deserialize(fs), Circle)
      Catch e As SerializationException
         Console.WriteLine("Failed to deserialize. Reason: " + e.Message)
         Throw 
      Finally
         fs.Close()
      End Try 

      ' To prove that the Circle deserialized correctly, display its area.
      Console.WriteLine("Object being deserialized: " + c.ToString())
   End Sub 
End Class
#using <mscorlib.dll>

using namespace System;
using namespace System::IO;
using namespace System::Collections;
using namespace System::Runtime::Serialization::Formatters::Binary;
using namespace System::Runtime::Serialization;

// This class is serializable and will have its OnDeserialization method
// called after each instance of this class is deserialized.
[Serializable]
__gc class Circle : public IDeserializationCallback
{
   Double m_radius;

   // To reduce the size of the serialization stream, the field below is 
   // not serialized. This field is calculated when an object is constructed
   // or after an instance of this class is deserialized.
public:
   [NonSerialized]
   Double m_area;

public:
   Circle(Double radius) 
   {
      m_radius = radius;
      m_area = Math::PI * radius * radius;
   }

   void OnDeserialization(Object* /*sender*/) 
   {
      // After being deserialized, initialize the m_area field 
      // using the deserialized m_radius value.
      m_area = Math::PI * m_radius * m_radius;
   }

public:
   String* ToString() 
   {
      return String::Format(S"radius= {0}, area= {1}", __box(m_radius), __box(m_area));
   }
};


void Serialize() 
{
   Circle* c = new Circle(10);
   Console::WriteLine(S"Object being serialized: {0}", c);

   // To serialize the Circle, you must first open a stream for 
   // writing. We will use a file stream here.
   FileStream* fs = new FileStream(S"DataFile.dat", FileMode::Create);

   // Construct a BinaryFormatter and use it to serialize the data to the stream.
   BinaryFormatter* formatter = new BinaryFormatter();
   try 
   {
      formatter->Serialize(fs, c);
   }
   catch (SerializationException* e) 
   {
      Console::WriteLine(S"Failed to serialize. Reason: {0}", e->Message);
      throw;
   }
   __finally 
   {
      fs->Close();
   }
}

void Deserialize() 
{
   // Declare the Circle reference.
   Circle* c = 0;

   // Open the file containing the data that we want to deserialize.
   FileStream* fs = new FileStream(S"DataFile.dat", FileMode::Open);
   try 
   {
      BinaryFormatter* formatter = new BinaryFormatter();

      // Deserialize the Circle from the file and 
      // assign the reference to our local variable.
      c = dynamic_cast<Circle*>(formatter->Deserialize(fs));
   } 
   catch (SerializationException* e) 
   {
      Console::WriteLine(S"Failed to deserialize. Reason: {0}", e->Message);
      throw;
   }
   __finally 
   {
      fs->Close();
   }

   // To prove that the Circle deserialized correctly, display its area.
   Console::WriteLine(S"Object being deserialized: {0}", c);
}

[STAThread]
int main() 
{
   Serialize();
   Deserialize();
}

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0
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